Stein Research Group | University of Houston | Department of Chemical & Biomolecular Engineering

About Our Research

Physics and Chemistry of Polymers.

Our research is focused on the design, characterization, and optimization of polymer-based electronic materials. Our work can be applied to low-cost solar cells, semiconductor device manufacturing, and biosensing.

Projection Lithography.

We are studying polymer imaging materials for optical lithography, which is the patterning technique used to define microelectronics circuitry. The goals of this program are to measure the chemical reactions that generate the images, build process models that incorporate ultra-thin film properties, and develop high-throughput screening methods for new materials.

Nanopatterning.

We are studying block copolymer self-assembly for applications in low-cost nanopatterning of semiconductor devices. The goals of this research effort are to control self-assembly in three-dimensions by tuning interactions at the free surface and substrate interfaces.

Solar Cells.

We are studying the variables that control power-conversion efficiency in polymer-based solar cells. We build model devices for fundamental studies of photocurrent generation using top-down lithography. Ultimately, our goal is to improve the device efficiency by controlling the active layer morphology.

People

Dr. Gila Stein

Assistant Professor of Chemical & Biomolecular Engineering, 2009-Present
NRC-NIST Postdoctoral Fellow, 2007-2008
Ph.D. Chemical Engineering, University of California, Santa Barbara, 2006
B.S. Chemical Engineering, Drexel University, 2002

E-mail: gestein "at sign" uh.edu

Graduate Students

Nikhila Mahadevapuram

B.S. Chemical Engineering, National Institute of Technology, Warangal, India, 2008
Research Interests: Organic photovoltaics, block copolymer self-assembly.
E-mail: nmahadev "at sign" mail.uh.edu

Indranil Mitra

Ph.D. Mathematical Physics, Saha Institute of Nuclear Physics, Kolkata, India
Research Interests: Directed self-assembly of block copolymers, nanopatterning, biomarker detection.
E-mail: imitra "at sign" mail.uh.edu

Suchanun (Bee) Moungthai

B.S. Chemistry, Kasetsart University, Thailand, 2006
Research Interests: Organic photovoltaics, dewetting in thin polymer films.
E-mail: smoungth "at sign" mail.uh.edu

Abhijit Patil

M.S. Chemical Engineering, University of Kentucky, 2009
B.S. Chemical Engineering, University Institute of Chemical Technology, Mumbai, India, 2007
Research Interests: Controlling image formation in photoresist thin films
E-mail: abhijit7.patil "at-sign'' gmail.com

Ginusha Perera

B.S. Chemical Engineering, University of Moratuwa, Sri Lanka, 2003
Research Interests: Chemically-amplified resists, sensors for molecular diagnostics
E-mail: gmperer2 "at sign" mail.uh.edu

Undergraduate Students

Adeline Mah

B.S. Chemistry, University of Houston, December 2012 (expected)
Research Interests: Lithography, surface chemistry, biosensors
E-mail: huizhen89 "at sign" gmail.com

UH Alumni

Thao Dinh, B.S. Chemical Engineering, May 2011
Thai Vu, B.S. Chemical Engineering, May 2011
Trang Pham, B.S. Chemical Engineering, December 2011
Gus Rajaendran, B.S. Chemical Engineering, May 2012

REU Alumni

Makenzie Dixon, Trinity University, Summer 2009
Amara Enemuo, City College of New York, Summer 2009
Leslie Scrof, Louisiana State University, Summer 2010
Alona Bozhchenko, Rice, Summer 2011

Visitors

Akil Chittaluru, Klein Oak High School, Summer 2011

The Lab

Facility & Equipment

1,400 square feet of newly renovated lab space
Three chemical fume hoods
J.A. Woolam M-2000 spectroscopic ellipsometer with focusing optics and Instec heat stage
Nikon LV150 reflected light microscope (BF/DF) with digital camera
Brewer CEE 200CB spin coater and bake plate
Dataphysics OCA 15EC contact angle goniometer
Keithly 2601A source measure unit
HE-453-2 Vacuum Atmospheres glove box equipped with SCS spin coater
Oriel 150W solar simulator
Two VWR vacuum ovens

Other Resources

Publications

Journal Articles

2012

A. Labiano, M. Dai, W-S Young, G.E. Stein, K. Cavicchi, T. Epps, B.D. Vogt, ``Impact of homopolymer pore expander on the morphology of mesoporous carbon films using organic-organic self-assembly," The Journal of Physical Chemistry C, 116, 6038-6046, 2012. [DOI]

2011

T. Vu, N. Mahadevapuram, G.M. Perera, G.E. Stein, ``Controlling Domain Orientations in Thin Films of AB and ABA Block Copolymers,'' Macromolecules, 44, 6121–6127, 2011. [DOI]
B.D. Vogt, V.L. Chavez, M. Dai, M.R. Croda Arreola, L. Song, D. Feng, D. Zhao, G.M. Perera, G.E. Stein, ``Impact of film thickness on the morphology of mesoporous carbon films using organic-organic self assembly,'' Langmuir, 27, 5607-5615, 2011. [DOI]

2010

G.M. Perera, G.E. Stein, J.A. Liddle, ``Spatial Coherence in Electron-Beam Patterning,'' Journal of Vacuum Science & Technology B, 28, 1048-1055, 2010. [DOI]
V. Mishra, S.-M. Hur, E.W. Cochran, G.E. Stein, G.H. Fredrickson, E.J. Kramer, ``Symmetry transition in thin films of diblock copolymer/homopolymer blends,'' Macromolecules, 43, 1942-1949, 2010. [DOI]
G.E. Stein, J.A. Liddle, A.L. Aquila, E.M. Gullikson,``Measuring the structure of epitaxially assembled block copolymer domains with soft x-ray diffraction,'' Macromolecules, 43, 433-441, 2010. [DOI]

2005 - 2008

C. Tang, J. Bang, G.E. Stein, G.H. Fredrickson, C.J. Hawker, E.J. Kramer, M. Sprung, J. Wang, ``Square packing and structural arrangement of ABC triblock copolymers in thin films,'' Macromolecules, 41, 4328-4339, 2008. [DOI]
G.E. Stein, E.J. Kramer, X. Li, J. Wang, ``Thickness dependent ordering in laterally confined monolayers of spherical domain block copolymers,'' Macromolecules, 40, 5791-5800, 2007. [DOI]
J. Bang, B.J. Kim, G.E. Stein, E.J. Kramer, C.J. Hawker, T.P. Russell, ``Effect of humidity on the ordering of PEO-based copolymer thin films,'' Macromolecules, 40, 7019-7025, 2007. [DOI]
G.E. Stein, E.W. Cochran, K. Katsov, G.H. Fredrickson, E.J. Kramer, X. Li, J. Wang, ``Symmetry breaking of in-plane order in confined copolymer mesophases,'' Physical Review Letters, 98, 158302, 2007. [DOI]
G.E. Stein, E.J. Kramer, X. Li, J. Wang, ``Layering transitions in thin films of spherical-domain block copolymers,'' Macromolecules, 40, 453-2460, 2007. [DOI]
G.E. Stein, E.J. Kramer, X. Li, J. Wang, ``Single crystal diffraction from two-dimensional block copolymer arrays,'' Physical Review Letters, 98, 086101, 2007. [DOI] (Cover)
V. Khanna, E. Cochran, A. Hexemer, G.E. Stein, G.H. Fredrickson, E.J. Kramer, X. Li, J. Wang, S.F. Hahn, ``Effect of chain architecture and surface energies on the ordering behavior of lamellar and cylinder forming block copolymers,'' Macromolecules, 39, 9346-9356, 2006. [DOI]
A. Hexemer, G.E. Stein, E.J. Kramer, S. Magonov, ``Block copolymer monolayer structure measured with scanning force microscopy moire patterns,'' Macromolecules, 38, 7083-7089, 2005. [DOI]

Book Chapters

G.E. Stein, ``Scattering Methods for Thin Polymer Films,'' In Functional Polymer Films: Characterization and Applications, R. Advincula, W. Knoll, Eds.; Wiley-VCH: Weinheim, 2011, pp. 669-694.